My iPhone is not syncing messages to my computer and now all of my contacts are gone. Can you please assist.
From what we understand, your messages from your iPhone aren't appearing on your computer. Also your contacts are not longer showing on the Mac. Were you using Messages in iCloud in order to have messages available on both devices? If so, we suggest making sure the setting is still enabled on both devices: Use Messages in iCloud
You also mentioned you're not seeing your contacts on your Mac. If you were using iCloud to sync contacts, make sure it is enabled: Set up and use iCloud Contacts
Hope this helps.